[HatchLifeRS]

If I had to guess it would be because of the tune. My tailpipe has some black soot as well with a tune. It could've happened without the tune, I just never paid attention before hand. However my Hyundai used to have black soot as well on an stock non-turbo engine. So personally I wouldn't be concerned about it. Although I would be curious to know why.

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[eddiefromcali]

What are your Fuel Trims like? Might have a boost leak and causing a rich condition. The tune will command the same fuel ratio as stock, so it shouldnt be tune related. This is likely due to a maintenance issue.

 

[Thebigzeus]

What are your Fuel Trims like? Might have a boost leak and causing a rich condition. The tune will command the same fuel ratio as stock, so it shouldnt be tune related. This is likely due to a maintenance issue.

I have boost leak tested the car into oblivion lol, only small leak is from atmospheric bypass valve and its a very small hiss, in the past had many leaks (intake manifold, throttle body). From 20-10psi on boost leak test it takes over 40 seconds which I believe is more than acceptable. I ran some diagnostics today, will check fuel trims once I am back at pc. Long term trims I suppose?

 

[eddiefromcali]

Yeah, LTFT should be close to zero.

 

[Thebigzeus]

Yeah, LTFT should be close to zero.

Here they are:

 

[Thebigzeus]

I guess it's good.

 

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We run a richer AFR at wide open throttle than the stock tune, which is quite lean due to the low boost. It's normal to see some soot with a tune. AFR at part throttle and idle is the same as stock though.

 

[Thebigzeus]

So an update to this, seems lately the lftf are way off, as the engine heats they get worse... How could that be? Seems to run pretty good, am I just looking into the numbers too much? (I just put green giants in, so I am watching this on purpose) Not sure where to ask questions, nothing against Jerry, but he just sends one sentence back and an updated tune. I would like a little more.

 

[Muz]

I've been chasing a similar rich issue, but definitely seems like a boost leak here (according to BNR) still yet to verify the exact leak though. Not an issue from changing to 42# injectors from stock. Plugs are quite black with soot/carbon. It's not a tune issue either, just really hard to find this boost leak. I've been searching but haven't found it yet. Can't 100% verify it's a boost leak until it's fixed though...

 

[Thebigzeus]

They aren't going quite as negative with recent tune and plug updates, but it's still weird to me. Car seems to run fine... I guess it's a dont worry about it. I got rid of the NGK BKR plugs and got new AC Delco ones, seems to burn cleaner, but I dont know if that would affect fuel trims, maybe?

 

[Thebigzeus]

Still dealing with this, its very weird as the engine heats they get more negative... What does that mean? Just as in the graph above.

 

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Check PMs

 

[Muz]

Hey Bigzeus, any more info on this would be appreciated.
Thanks, Muz...